来源：https://stackoverflow.com/questions/9878020/how-do-i-get-the-user-agent-with-flask

方法一：直接使用字符串

from flask import request
request.headers.get('User-Agent')

方法二：使用 request.user_agent 对象

例如

request.user_agent.platform

• platform (windows, linux, macos, etc.)
• browser (chrome, firefox, msie, etc.)
• version
• language
• string (== request.headers.get('User-Agent'))